State Water Board takes action to protect groundwater in overdrafted Tule Subbasin

SACRAMENTO – To protect the long-term viability of groundwater supplies and critical water infrastructure for communities, the State Water Resources Control Board today placed the overdrafted Tule Groundwater Subbasin in probationary status under the landmark Sustainable Groundwater Management Act (SGMA).

Overdraft in the Tule Subbasin is causing the land surface to sink, damaging critical infrastructure, like the Friant-Kern Canal. Subsidence along the Friant-Kern Canal has caused nearly a half billion dollars in damage. This damage is currently being repaired, but ongoing subsidence threatens the integrity of these repairs before they are even complete. In addition, overdraft threatens groundwater levels and drinking water quality and could have disparate impacts on communities that rely on shallow wells.

During today’s hearing, board staff presented findings from their final report on the Tule Subbasin, which describes the deficiencies in the subbasin’s groundwater sustainability plan (GSP) that have led to the probationary designation.

“The action we have taken today will protect groundwater resources in the Tule Subbasin for communities that rely on it for basic needs, like drinking water, while local agencies work to improve their sustainability plans,” said Joaquin Esquivel, chair of the State Water Board. “The ultimate goal of SGMA, and the probationary process, is for groundwater subbasins to be managed sustainably at the local level. We are committed to helping groundwater agencies make that happen by providing guidance and support.”

On average, water is being pumped out of the Tule Subbasin faster than it is recharged by rain and other sources. It is causing the aquifer to lose enough water to supply at least the equivalent of 500,000 households with water every year.

An analysis conducted by the California Department of Water Resources (DWR) found that over 550 domestic wells could go dry if recent drought conditions returned. Many of the wells that could go dry are in economically disadvantaged communities and communities of color.

Groundwater is one of California’s greatest natural resources, making up nearly 40% of California’s total water supply on an average annual basis, but nearly 60% in critically dry years. About 85% of Californians rely on groundwater for some portion of their water needs. The Legislature passed SGMA in 2014 to address groundwater overdraft and bring subbasins into balanced levels of pumping and groundwater recharge.

Groundwater sustainability agencies (GSAs) have been working to address deficiencies in their groundwater sustainability plans (GSPs). GSAs recently submitted revised GSPs for review. Board staff conducted a tentative review and found that many deficiencies appear to have been addressed. But key deficiencies remain, especially concerning ongoing subsidence and its impacts to critical infrastructure, like the Friant- Kern Canal.

During probation, board staff will continue to work with GSAs to address remaining deficiencies in their GSPs so that intervention is no longer needed. The board will also collect the groundwater extraction information necessary to inform sustainable groundwater management. Ninety days after probation begins, most groundwater pumpers in the Tule subbasin will be required to begin recording their groundwater pumping, and eventually, report that information to the board. Data on where and how much pumping is occurring will provide the board with critical information about how sustainable management can be achieved.

If deficiencies are not addressed within a year, the board could move into the second phase of the state intervention process, called an interim plan. Only during this second phase, after another public hearing, could the board impose pumping restrictions on subbasins or issue fines for exceeding water allotments.

The board partially excluded groundwater extractors within two GSAs – the Delano Earlimart Irrigation District and Kern-Tulare Water District – from reporting requirements and associated fees on the condition that they remain in compliance with management actions implemented by their GSAs. The board granted these exclusions based on findings that these GSAs adequately managed groundwater in their portions of the subbasin. However, the board did not grant these GSAs a full exclusion from probationary status since their plans do not yet meet SGMA’s requirements for full exclusions. Staff will recommend full exclusions from probation if all remaining plan deficiencies are addressed by the GSAs.

In 2023, DWR determined that GSPs for six critically overdrafted groundwater subbasins, including the Tule Subbasin, were inadequate under SGMA because they would not bring about sustainable groundwater use by 2040. Following these determinations, as required by the law, DWR referred the six subbasins to the board for possible state intervention. This is the second subbasin the board has placed on probationary status; in April, the board also designated the Tulare Lake subbasin as probationary.

More information about the board’s implementation of SGMA can be found on its website.

The State Water Board’s mission is to preserve, enhance and restore the quality of California’s water resources and drinking water for the protection of the environment, public health, and all beneficial uses, and to ensure proper resource allocation and efficient use for present and future generations.